/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2001-2004 Caucho Technology, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Caucho Technology (http://www.caucho.com/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "Burlap", "Resin", and "Caucho" must not be used to
 *    endorse or promote products derived from this software without prior
 *    written permission. For written permission, please contact
 *    info@caucho.com.
 *
 * 5. Products derived from this software may not be called "Resin"
 *    nor may "Resin" appear in their names without prior written
 *    permission of Caucho Technology.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL CAUCHO TECHNOLOGY OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
 * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @author Scott Ferguson
 */

package com.caucho.burlap.client;

import com.caucho.burlap.io.AbstractBurlapInput;
import com.caucho.burlap.io.BurlapOutput;

import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import java.util.logging.*;

/**
 * Proxy implementation for Burlap clients.  Applications will generally
 * use BurlapProxyFactory to create proxy clients.
 */
public class BurlapProxy implements InvocationHandler {
    private static final Logger log = Logger.getLogger(BurlapProxy.class.getName());

    private BurlapProxyFactory _factory;
    private URL _url;

    BurlapProxy(BurlapProxyFactory factory, URL url) {
        _factory = factory;
        _url = url;
    }

    /**
     * Returns the proxy's URL.
     */
    public URL getURL() {
        return _url;
    }

    /**
     * Handles the object invocation.
     *
     * @param proxy the proxy object to invoke
     * @param method the method to call
     * @param args the arguments to the proxy object
     */
    public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
        String methodName = method.getName();
        Class[] params = method.getParameterTypes();

        // equals and hashCode are special cased
        if (methodName.equals("equals") && params.length == 1 && params[0].equals(Object.class)) {
            Object value = args[0];
            if (value == null || !Proxy.isProxyClass(value.getClass()))
                return new Boolean(false);

            BurlapProxy handler = (BurlapProxy) Proxy.getInvocationHandler(value);

            return new Boolean(_url.equals(handler.getURL()));
        } else if (methodName.equals("hashCode") && params.length == 0)
            return new Integer(_url.hashCode());
        else if (methodName.equals("getBurlapType"))
            return proxy.getClass().getInterfaces()[0].getName();
        else if (methodName.equals("getBurlapURL"))
            return _url.toString();
        else if (methodName.equals("toString") && params.length == 0)
            return getClass().getSimpleName() + "[" + _url + "]";

        InputStream is = null;

        URLConnection conn = null;
        HttpURLConnection httpConn = null;
        try {
            conn = _factory.openConnection(_url);

            httpConn = (HttpURLConnection) conn;

            httpConn.setRequestMethod("POST");
            conn.setRequestProperty("Content-Type", "text/xml");

            OutputStream os;

            try {
                os = conn.getOutputStream();
            } catch (Exception e) {
                throw new BurlapRuntimeException(e);
            }

            BurlapOutput out = _factory.getBurlapOutput(os);

            if (!_factory.isOverloadEnabled()) {
            } else if (args != null)
                methodName = methodName + "__" + args.length;
            else
                methodName = methodName + "__0";

            if (log.isLoggable(Level.FINE))
                log.fine(this + " calling " + methodName + " (" + method + ")");

            out.call(methodName, args);

            try {
                os.flush();
            } catch (Exception e) {
                throw new BurlapRuntimeException(e);
            }

            if (conn instanceof HttpURLConnection) {
                httpConn = (HttpURLConnection) conn;
                int code = 500;

                try {
                    code = httpConn.getResponseCode();
                } catch (Exception e) {
                }

                if (code != 200) {
                    StringBuffer sb = new StringBuffer();
                    int ch;

                    try {
                        is = httpConn.getInputStream();

                        if (is != null) {
                            while ((ch = is.read()) >= 0)
                                sb.append((char) ch);

                            is.close();
                        }

                        is = httpConn.getErrorStream();
                        if (is != null) {
                            while ((ch = is.read()) >= 0)
                                sb.append((char) ch);
                        }
                    } catch (FileNotFoundException e) {
                        throw new BurlapRuntimeException(code + ": " + String.valueOf(e));
                    } catch (IOException e) {
                    }

                    if (is != null)
                        is.close();

                    throw new BurlapProtocolException(code + ": " + sb.toString());
                }
            }

            is = conn.getInputStream();

            AbstractBurlapInput in = _factory.getBurlapInput(is);

            return in.readReply(method.getReturnType());
        } catch (BurlapProtocolException e) {
            throw new BurlapRuntimeException(e);
        } finally {
            try {
                if (is != null)
                    is.close();
            } catch (IOException e) {
            }

            if (httpConn != null)
                httpConn.disconnect();
        }
    }

    public String toString() {
        return getClass().getSimpleName() + "[" + _url + "]";
    }
}
